AREA FORECAST DISCUSSION

 
 FXUS66 KSGX 092239
 AFDSGX
 
 AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE SAN DIEGO CA
 240 PM PST TUE FEB 9 2010
 
 .SYNOPSIS...
 A COLD LOW PRESSURE SYSTEM MOVING DOWN THE CALIFORNIA COAST WILL 
 TRACK SOUTHEAST ACROSS THE COASTAL WATERS TONIGHT. THE LOW IS 
 FORECAST TO TRACK EAST ACROSS NORTHERN BAJA CALIFORNIA EARLY 
 WEDNESDAY AND THEN MOVE EAST OF THE REGION BY WEDNESDAY EVENING. 
 THIS WILL BRING PERIODS OF PRECIPITATION THROUGH WEDNESDAY TO 
 SOUTHWEST CALIFORNIA WITH A CHANCE OF THUNDERSTORMS. SNOW LEVELS 
 WILL LOWER TO NEAR 3000 FEET LATE TONIGHT THROUGH EARLY WEDNESDAY. 
 DRY AND GRADUALLY WARMER THURSDAY THROUGH FRIDAY. STRONGER HIGH 
 PRESSURE THIS WEEKEND MAY BRING WARMING TO ABOVE SEASONAL AVERAGES 
 THROUGH TUESDAY AND WEAK OFFSHORE WINDS ARE POSSIBLE.
 
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 .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
 SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
 COUNTIES...
 
 
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 .NEAR TERM...TONIGHT THROUGH WEDNESDAY MORNING...
 STRONG COLD FRONT MOVING SOUTHEAST 22 KNOTS/25 MPH...ACROSS FORECAST 
 AREA TONIGHT. MODELS IN GOOD AGREEMENT ON STRENGTH AND TRACK OF 
 UPPER LOW...FORECAST TO BE CENTERED OVER SAN DIEGO BY 4 AM WEDNESDAY 
 AND CENTERED OVER NORTHERN GULF OF CALIFORNIA BY 4 PM WEDNESDAY.  
 COLD CORE...WITH 500 MB TEMPERATURES OF -30C AND 850 MB TEMPERATURES 
 -4C PASSING ACROSS  SOUTHERN CALIFORNIA BIGHT AND RELATIVELY WARM 
 SEA SURFACE/925 MB TEMPERATURES WILL MAKE FOR VERY UNSTABLE LAPSE 
 RATES THROUGH EARLY WEDNESDAY MORNING. MAY HAVE SEVERE WEATHER 
 WATCHES OUT BEFORE THIS EVENT IS OVER. 
 
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 .REMAINDER SHORT TERM...WEDNESDAY AFTERNON THROUGH FRIDAY... 
 FOR WEDNESDAY AFTERNOON SLOW WINDING DOWN OF SHOWER ACTIVITY BUT 
 MADE SOME MINOR ADJUSTMENTS TO ENDING TIME OF PRECIPITATION EAST 
 SLOPES OF MOUNTAINS/LOWER DESERTS TO REFLECT WRAP AROUND 
 MOISTURE/OROGRAPHIC LIFTING STILL PRODUCING LIGHT SHOWERS INTO EARLY 
 EVENING HOURS WEDNESDAY. WEDNESDAY NIGHT THROUGH THURSDAY DRYING OUT 
 UNDER THE BUILDING HIGH PRESSURE RIDGE. MAY REINTRODUCE FROST FOR 
 INLAND VALLEYS WEDNESDAY NIGHT/THURSDAY MORNING AS WINDS FORECAST TO 
 GO TO NEAR CALM AND SKIES TO BE CLEAR. LOWER DESERT AREAS WILL 
 LIKELY STILL HAVE ENOUGH WIND TO KEEP FROST FROM FORMING THERE. FLAT 
 RIDGE FOR FRIDAY WITH TROUGH PASSING INLAND TO THE NORTH WILL ALLOW 
 MID/HIGH CLOUDS TO MOVE ACROSS THE FORECAST AREA.
 
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 .LONG TERM...FRIDAY NIGHT THROUGH NEXT TUESDAY...
 RIDGE REBUILDS SATURDAY AND SUNDAY CREATING A FAVORABLE PATTERN FOR  
 LIGHT TO MODERATE OFFSHORE WINDS. RIDGE FLATTENS SOMEWHAT MONDAY AND 
 TUESDAY AS TROUGHS PASS INLAND WELL TO THE NORTH. 
 
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 .AVIATION...
 092000Z...COLD FRONT APPROACHING FROM THE NORTHWEST IS EXPECTED TO 
 MOVE THROUGH THIS AFTERNOON AND EVENING. THE LEADING EDGE WAS 
 ALREADY MOVING INTO THE KSNA/KONT AREA AND SHOULD REACH KSAN BY 21Z. 
 THE MAIN FRONT SHOULD FOLLOW WITHIN AN HOUR OR TWO. EXPECT MOSTLY 
 OVERCAST LAYERS OF STRATOCU/CU AND ISOLATED CBS WITH BASES BETWEEN 
 FL015 AND FL030 THROUGH THE AFTERNOON AND EARLY EVENING. 
 VISIBILITIES MOSTLY 3 TO 5 MILES IN SHOWERS EXCEPT LOCALLY 1 MILE IN 
 MODERATE TO HEAVY SHOWERS/TSTMS. BEHIND THE FRONT AND CONTINUING 
 THROUGH THE NIGHT INTO WEDNESDAY MORNING...MOSTLY BROKEN CU/TCU WITH 
 BASES BETWEEN 2000 AND 3000 FEET AND TOPS TO 10000 FEET MSL EXCEPT 
 TOPS TO FL250 IN ISOLATED TSTMS. MOUNTAINS WILL BE MOSTLY OBSCURED 
 THROUGH WEDNESDAY MORNING. BECOMING MOSTLY SCATTERED CONDITIONS BY 
 WEDNESDAY AFTERNOON.  HORTON
 
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 .MARINE...
 WATERSPOUTS HAVE BEEN REPORTED TODAY AND POTENTIAL EXISTS FOR 
 ADDITIONAL WATERSPOUTS TO DEVELOP THROUGH WEDNESDAY MORNING. SEE 
 SPECIAL MARINE WARNINGS AND MARINE WEATHER STATEMENT.
 
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 .SGX WATCHES/WARNINGS/ADVISORIES...
 CA...WINTER WEATHER ADVISORY BELOW 4500 FEET UNTIL 6 AM PST 
      WEDNESDAY FOR SAN BERNARDINO COUNTY MOUNTAINS-RIVERSIDE COUNTY
      MOUNTAINS-SAN DIEGO COUNTY DESERTS-SAN DIEGO COUNTY MOUNTAINS.
 
      WINTER WEATHER ADVISORY ABOVE 3000 FEET UNTIL 6 AM PST 
      WEDNESDAY FOR APPLE AND LUCERNE VALLEYS-COACHELLA VALLEY-
      SAN DIEGO COUNTY DESERTS-SANTA ANA MOUNTAINS AND FOOTHILLS.
 
      FLASH FLOOD WATCH THROUGH 6 AM PST WEDNESDAY FOR ORANGE 
      COUNTY COASTAL AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY
      VALLEYS-THE INLAND EMPIRE-SANTA ANA MOUNTAINS AND FOOTHILLS.
 
      WINTER STORM WARNING ABOVE 4500 FEET UNTIL 6 AM PST WEDNESDAY 
      FOR RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-
      SAN DIEGO COUNTY MOUNTAINS.
 
      SPECIAL WEATHER STATEMENT TO SUMMARIZE ABOVE AND COVER OTHER
      EFFECTS IN REMAINING ZONES.
 
 PZ...MARINE WEATHER STATEMENT BOTH INNER AND OUTER COASTAL
      WATERS FOR THREAT OF THUNDERSTORMS AND WATERSPOUTS THROUGH
      WEDNESDAY MORNING.
 
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 $$
 
 PUBLIC...BALFOUR
 AVIATION/MARINE...HORTON
 
 NWS ON THE WEB AT WEATHER.GOV/SANDIEGO